# Calculus

posted by
**Sara**
.

Given f and g are differentiable functions and

f(a)=-4, g(a)=c, g(c)=10, f(c)=15

f'(a)=8, g'(a)=b, g'(c)=5, f'(c)=6

If h(x)=f(g(x)). find h'(a)?

i'm not really sure how to get the answer. g'(a)=b, f'(b)=? How do i go about doing this. My reasoning must be wrong.

h'(x)= f'(g(x))*g'(x)

if x=a

h'(a)=f'(g(a))*g'(a)

=f'(c) * b = 6b

check my thinking.